However you prefer to consume your water – basic tap, elaborate French mineral or straight from the ditch – you’d know if you weren’t getting enough. Or your undertaker would. But the chances are you don’t really understand why it’s so important or just what it’s up to, so here are 20 liquid questions you ought to be asking, answered.
1. How does it get into your system?
You start taking water on board as soon as it goes in: unlike Nando’s or foie gras, say, small amounts are absorbed by osmosis in your mouth and throat as you swallow. Water is ingested the same way all the way down until any excess is excreted.
2. What does water do in the body?
It allows you to digest your food, it lubricates everything from your joints to your eyes to your mouth to more intimate parts. Sweating helps the body regulate its temperature. At a cellular level, pretty much every part of the body is essentially suspended in water – it’s also the key to the body’s moving things around. It provides the medium for the body to get rid of toxins and things it doesn’t need. In short, if you don’t drink water, everything stops, overheats and you die.
3. How does your body avoid this fate?
Your blood vessels have receptors called baroreceptors and osmoreceptors that respectively read the fluid volume and solute concentration (the amount of stuff dissolved in it) of your blood – if either dips too low, signals are sent to your brain that it interprets to make you feel thirsty, and you reach for a refreshing beverage.
4. Pub mythology says 90% of my body is water – can this possibly be true?
Get a new pub – the average adult male is about 60% water, the average female 55%. This varies according to age – babies and children have a lot more water, for example – and to fitness level, as fatty tissue contains less water than its leaner equivalents.
5. At what point do you become thirsty?
Your hydration level needs to sink 2-3% as a percentage of body mass for you to feel thirsty, but interestingly you only need to be 1% dehydrated for mental and physical performance to be impaired. Is Malcolm in accounts useless, or just in need of a Fruit Shoot? Who knows. But if his hydration sinks to 15-20%, you’ll have one fewer office birthday to worry about.
6. How important is water when you’re exercising?
Here’s a radical revelation: it’s really, really important. As you’ve figured out by now, your body badly needs water to function properly, and functioning properly is kind of the whole idea of a workout. Being dehydrated means, as you’ve seen, having to work harder to do less, your joints are less spry and you’ll have less water to sweat out to cool yourself – you can cramp up faster, and in general won’t be as effective.
7. How does dehydration affect the body?
When Billy Bob Thornton in Armageddon says an asteroid hit will be “All the worst parts of the Bible” – that’s what dehydration does to your body. You can survive for a long time without food, but without water, you’re likely to be in the ground within a week. With less water in your system, your blood volume decreases, meaning your heart has to work harder to pump it round. Your blood vessels also constrict, so don’t be surprised when dehydration headaches strike.
8. What do the kidneys do?
For water in the body, the kidneys are the point at which a decision is made as to whether it’ll be staying to slosh around your body, or squirted out to make its own way in the world. As blood passes through the kidneys, the water is either filtered out to be sent to be peed out along with excess salt, glucose and urea, or left alone, depending on your levels of hydration. The brain governs this via a hormone named vasopressin, which essentially determines if your blood keeps its water or not.
9. Can you really die from drinking too much water?
Yes. It’s rare but falling victim to water intoxication is not as difficult to do as you might think. The American Chemistry Society says that six litres of water would be enough to kill a 75kg man if consumed over a short period of time. This over-hydration can cause an electrolyte imbalance that affects brain function. The most common circumstances for this to happen are in extreme endurance events, water-drinking contests or after taking ecstasy.
10. Home filters – do they do anything?
Tap water in the UK is among the cleanest in the world – while water filters do remove various trace amounts of bacteria and the disinfectants used to clean the water, humanity has so far managed to avoid dying out since the invention of the water mains. Still, if you prefer the taste, go crazy.
11. How many people has your glass of “Thames” water passed through?
There’s an urban myth that your glass of tap water has been through seven people, but it’s very tricky to prove with any convincing degree of accuracy. One thing you can be certain of is that it’s passed through a whole lot of living things, and since the amount of water in the world is theoretically finite, you’re part of a chain that goes all the way back to the dinosaurs and beyond.
12. What is mineral water?
It’s not a huge surprise: it’s water that contains a combination of minerals, such as, say, salts, that is supposedly unique to the spring that produced it. In the EU, you can only call it mineral water if it’s been bottled at the source and has undergone only limited treatment, such as the removal of less appetising components such as arsenic.
13. Can you absorb any minerals from mineral water?
Sure – your body absorbs some of the latent minerals in non-mineral water, so mineral water just provides more of them for your system to take in. Most of the absorption takes place in the small intestine, where, if you want to talk technical, the minerals arrive as charged ions in a colloidal solution, which facilitates their absorption.
14. What’s in tap water?
Chemicals are used to disinfect water when it is treated, including chlorine, ozone, hydrogen peroxide and aluminium sulfate – trace amounts can remain, varying region to region. Lead and bacteria can also be picked up from old pipes. However, there’s not much cause for concern – in 2015, British water’s compliance with EU standards hovered between 99-100%.
15. What is coconut water?
No surprises here – it’s the liquid found inside a young coconut, and it’s the health fad du jour. Its adherents may be onto something, though – despite the excited claims of some marketing departments, it really is low in fat and sodium and pretty nutritious. That said, it has loads of sugar, even if it’s naturally occurring.
16. What is vitamin water?
A brand of water “enhanced” with vitamins, minerals – and a whole lot else. Despite being marketed as a healthy alternative to fizzy drinks, you’re still probably better off with good old normal water, with the added sweeteners and fructose seldom being a good idea.
17. What is honey water?
Spring water lightly sweetened with honey, rather than the usual refined sugars or similar synthetic gunk. You could probably make your own without too much fuss, to be honest.
18. What is cactus water?
One of the latest in a long line of products seeking the attention of those wishing to hydrate as fashionably as possible, cactus water is from the fruit (not the cactus itself, survival obsessives) of the prickly pear cactus. Lower in cals and sugar than coconut water, but twice as expensive.
19. Is it healthier to drink warm water?
There’s a myth that drinking hot water helps you lose weight by “jump starting” your metabolism: unfortunately, it’s baloney. However, since it stays in the stomach a little longer than its colder counterpart, warm water may help you stay full – but there’s not a huge amount of evidence for this.
20. What’s the difference between hard and soft water?
Hard water contains minerals like calcium and magnesium; soft water has (usually) been treated, and only contains sodium. Hard water is usually more pleasant to drink, while soft water is easier to wash with as it lathers with soap easier, and doesn’t leave limescale on appliances and glasswear.
